Are there any solutions for network connectivity issues on my Alcatel Idol X+?

Idol X+ was good on 4.2.2 , after upgrading to 4.4.2, almost every other day the mobile is not reachable as the network tower switching doesn't happen and the phone gets stuck on the network signal tower.
No fixes are being talked about from Alcatel

Bring the phone to the carrier and see if they can flash 4.4.2 back on it, since the phone is useless the way it is. (If not, and you bought the phone from them, they may be in breach of contract [which means no ETF, since you can legally void the contract at will]. Unless they're willing to replace the phone with another phone you're happy with at the same or lower price, or at a higher price if you're willing to pay the difference. They have to "make you whole". Sending you the update was their doing, so they're responsible for fixing the problems it caused - whether Alcatel is willing to do anything or not. [That's between your carrier and Alcatel - you're not a party to that problem.])

Depending on your carrier, this is going to be anywhere from "sure, we'll just reflash it" or "sure, which phone would you like to replace it with" to your hiring an attorney to remind the carrier of the way the law works. (Some carriers are great to work with - others I wouldn't take service from if they paid me every month. Well, I would, but I'd use a phone on a different carrier and just consider the money free income. Sometimes the frustration you get from asking for help isn't worth any benefit using that carrier gives you.)